<!DOCTYPE html>
<html>
    <!-- this code taken from https://github.com/muaz-khan/WebRTC-Experiment/tree/master/Chrome-Extensions/desktopCapture -->
    <head>
        <!-- head; this <link> tag MUST be in <head> section -->
        <link rel="chrome-webstore-item" href="https://chrome.google.com/webstore/detail/your-chrome-extension-id">
    </head>
    <body>
        <!-- body; the button element that is used to invoke inline installation -->
        <button onclick="" id="install-button" style="padding: 0;background: none;height: 61px;vertical-align: middle;cursor:pointer;">
            <img src="https://www.webrtc-experiment.com/images/btn-install-chrome-extension.png" alt="Add to Chrome">
        </button>

        <script>
            document.querySelector('#inline-install').onclick = function() {
                !!navigator.webkitGetUserMedia 
                    && !!window.chrome 
                    && !!chrome.webstore 
                    && !!chrome.webstore.install && 
                chrome.webstore.install(
                    'https://chrome.google.com/webstore/detail/your-chrome-extension-id', 
                    successCallback, 
                    failureCallback
                );
            };

            function successCallback() {
                location.reload();
            }

            function failureCallback(error) {
                alert(error);
            }
        </script>
    </body>
</html>